MySQL One to Many remove specific 'many' - mysql

Question

I have a database with a one to many relationship (venues, with associated categories) like so:
venue_id | venue_name
---------------------
1 | venue1
2 | venue2
and categories
venue_id | category_id
---------------------
1 | 5
2 | 7
1 | 8
2 | 5
I want to show all venues that HAVE category_id of 5, but dont have category_id of 7 and 8. I tried using a join like so:
SELECT distinct(`venue_to_category`.`venue_id`),`venue_name`
FROM `venue_to_category` INNER JOIN `venues`
ON `venues`.venue_id = `venue_to_category`.venue_id
WHERE `category_id` != 7
AND `category_id` != 8
AND `category_id` = 5
But it is not returning the correct results (in fact I am unsure the results it is returning)

Answer 1

2 Things in your case
Get data where category_id = 5 and not 7 or 8
Get data where category_id = 5 and not both 7 and 8
For the first one you can use
select
v.venue_id,
v.venue_name
from venues v
join categories c on c.venue_id = v.venue_id
where c.category_id = 5
AND NOT EXISTS
(
select 1 from categories c1 where v.venue_id = c1.venue_id
AND c1.category_id in (7,8)
);
For the 2nd one
select
v.venue_id,
v.venue_name
from venues v
join categories c on c.venue_id = v.venue_id
where c.category_id = 5
AND NOT EXISTS
(
select 1 from categories c1 where v.venue_id = c1.venue_id
AND c1.category_id in (7,8) having count(*) = 2
);
DEMO

Answer 2

When doing a search function of your site. Match and Against is better than Like sql statement. The field must be set to FullText match the term on the field:
SELECT vc.venue_id, venue_name FROM venue_to_category vc, venues v WHERE MATCH(category_id) AGAINST('-7 -8 +5');
You can also use the IN BOOLEAN MODE to allow operators in the sql statement. eg. ...
MATCH(category_id) AGAINST('-7 -8 +5' IN BOOLEAN MODE) ...
(-) minus sign that means nothing should match '-7' '-8'
(+) the word must be present in the match.
There are many other operators to be used. Refer to this page for more operator and explanation

Answer 3

Try
SELECT distinct `venue_to_category`.`venue_id` ,`venue_name`
FROM `venue_to_category` INNER JOIN `venues`
ON `venues`.venue_id = `venue_to_category`.venue_id
WHERE `category_id` <> 7
AND `category_id` <> 8
AND `category_id` = 5
or
SELECT distinct `venue_to_category`.`venue_id` ,`venue_name`
FROM `venue_to_category` INNER JOIN `venues`
ON `venues`.venue_id = `venue_to_category`.venue_id
WHERE `category_id` NOT IN (7,8)
AND `category_id` = 5
Note: distinct is not a function. And for your example you could leave it out entirely, because there are no duplicate rows.

Answer 4

SELECT v.id, v.name
FROM venues v
JOIN venue_to_category vc
ON vc.venue_id=v.id
AND vc.category_id=5
WHERE NOT EXISTS (
SELECT 1
FROM venue_to_category vci
WHERE vci.venue_id = v.id
AND vci.category_id IN (7,8)
);